Common stock shares no longer subject to forfeiture.

No definition available.

Name:	gnpk_CommonStockSharesNoLongerSubjectToForfeiture
Namespace Prefix:	gnpk_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt instrument convertible into shares amount.

+ References

No definition available.

+ Details

Name:	gnpk_DebtInstrumentConvertibleIntoSharesAmount
Namespace Prefix:	gnpk_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Fees and expenses related party transactions.

+ References

No definition available.

+ Details

Name:	gnpk_FeesAndExpensesRelatedPartyTransactions
Namespace Prefix:	gnpk_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Lock in period of shares held by the initial shareholders.

+ References

No definition available.

+ Details

Name:	gnpk_LockInPeriodOfSharesHeldByTheInitialShareholders
Namespace Prefix:	gnpk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of consecutive trading days for determining the share price.

+ References

No definition available.

+ Details

Name:	gnpk_NumberOfConsecutiveTradingDaysForDeterminingTheSharePrice
Namespace Prefix:	gnpk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of trading days for determining the share price.

+ References

No definition available.

+ Details

Name:	gnpk_NumberOfTradingDaysForDeterminingTheSharePrice
Namespace Prefix:	gnpk_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of common stock outstanding.

+ References

No definition available.

+ Details

Name:	gnpk_PercentageOfCommonStockOutstanding
Namespace Prefix:	gnpk_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Sale of stock for services received issue price per share.

+ References

No definition available.

+ Details

Name:	gnpk_SaleOfStockForServicesReceivedIssuePricePerShare
Namespace Prefix:	gnpk_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Carrying value as of the balance sheet date of payments made in excess of existing cash balances, which will be honored by the bank but reflected as a loan to the entity. Overdrafts generally have a very short time frame for correction or repayment and are therefore more similar to short-term bank financing than trade financing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 10
-Section 45
-Paragraph 10
-URI http://asc.fasb.org/extlink&oid=99376301&loc=d3e1243-112600

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_BankOverdrafts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Face amount or stated value per share of common stock.

+ References

+ Details

Name:	us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares of common stock outstanding. Common stock represent the ownership interest in a corporation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_CommonStockSharesOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120520924&loc=SL6031898-161870

+ Details

Name:	us-gaap_DebtInstrumentConvertibleConversionPrice1
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=119993939&loc=d3e28551-108399

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=114775985&loc=d3e28878-108400

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(2))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (bbb)(2)
-URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258

+ Details

Name:	us-gaap_DebtInstrumentMaturityDate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

Name:	us-gaap_SharePrice
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	instant

- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesIssuedForServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of new stock issued during the period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Number of shares (or other type of equity) forfeited during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationForfeited
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

Value of stock issued in lieu of cash for services contributed to the entity. Value of the stock issued includes, but is not limited to, services contributed by vendors and founders.

+ References

No definition available.

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueIssuedForServices
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=120397183&loc=d3e187085-122770

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(28))
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

+ Details

Name:	us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Number of shares of common stock subject to repurchase or cancellation determined by relating the portion of time within a reporting period that these shares have been outstanding to the total time in that period. Common stock subject to repurchase are outstanding common shares that are contingently returnable (that is, subject to recall).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=121326447&loc=d3e2646-109256

+ Details

Name:	us-gaap_WeightedAverageNumberOfSharesCommonStockSubjectToRepurchaseOrCancellation
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	gnpk_ClassOfStockSubCategoryAxis=gnpk_FounderSharesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionsByRelatedPartyAxis=gnpk_SponsorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=gnpk_AdministrativeServicesAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RelatedPartyTransactionAxis=gnpk_WorkingCapitalLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_SubsidiarySaleOfStockAxis=us-gaap_OverAllotmentOptionMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=gnpk_FounderSharesSubjectToForfeitureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassBMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=gnpk_FounderSharesClassBCommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gnpk_LockInPeriodAxis=gnpk_LockInPeriodOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_CommonClassAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	gnpk_LockInPeriodAxis=gnpk_LockInPeriodTwoMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=gnpk_PrivatePlacementWarrantsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Related Party Transactions - Additional Information (Detail) - USD ($)					3 Months Ended	5 Months Ended
	Jan. 07, 2021	Nov. 27, 2020	Nov. 16, 2020	Jul. 30, 2020	Mar. 31, 2021	Dec. 31, 2020
Founder Shares [Member]
Related Party Transaction [Line Items]
Percentage of common stock outstanding					20.00%
Sponsor [Member]
Related Party Transaction [Line Items]
Stock shares issued during the period for services value				$ 25,000	$ 25,000
Sale of stock for services received issue price per share				$ 0.004
Debt instrument face value					$ 300,000
Debt instrument maturity date					Mar. 31, 2021
Sponsor [Member] \| Administrative Services Agreement [Member]
Related Party Transaction [Line Items]
Fees and expenses related party transactions					$ 51,968
Sponsor [Member] \| Working Capital Loan [Member]
Related Party Transaction [Line Items]
Working capital loans outstanding					$ 0
Over-Allotment Option [Member]
Related Party Transaction [Line Items]
Stock issued during the period shares new issues		1,377,622
Over-Allotment Option [Member] \| Founder Shares Subject To Forfeiture [Member]
Related Party Transaction [Line Items]
Shares issued share based payment arrangement forfeited	218,094
Common stock shares subject to forfeiture	218,094
Number of trading days for determining the share price	45 days	45 days
Stock issued during the period shares new issues	218,094
Stock issued during period value new issues	$ 0
Over-Allotment Option [Member] \| Founder Shares [Member]
Related Party Transaction [Line Items]
Common stock shares subject to forfeiture			562,500
Percentage of common stock outstanding			20.00%
Common Class B [Member]
Related Party Transaction [Line Items]
Common stock par or stated value per share					$ 0.0001	$ 0.0001
Shares issued share based payment arrangement forfeited			1,437,500
Common stock shares outstanding			4,312,500		4,094,406	4,312,500
Common Class B [Member] \| Founder Shares [Member]
Related Party Transaction [Line Items]
Shares issued share based payment arrangement forfeited						218,094
Common stock shares outstanding						4,312,500
Common Class B [Member] \| Over-Allotment Option [Member]
Related Party Transaction [Line Items]
Common stock shares no longer subject to forfeiture		344,406
Common Class B [Member] \| Over-Allotment Option [Member] \| Founder Shares Subject To Forfeiture [Member]
Related Party Transaction [Line Items]
Number of trading days for determining the share price	45 days
Stock issued during the period shares new issues	218,094
Stock issued during period value new issues	$ 0
Founder Shares Class B Common Stock [Member]
Related Party Transaction [Line Items]
Stock shares issued during the period for services shares				5,750,000
Common stock par or stated value per share				$ 0.0001
Founder Shares Class B Common Stock [Member] \| Lock In Period One [Member]
Related Party Transaction [Line Items]
Lock in period of shares held by the initial shareholders					1 year
Common Class A [Member]
Related Party Transaction [Line Items]
Common stock par or stated value per share		$ 0.0001			$ 0.0001	$ 0.0001
Common stock shares outstanding					4,498,339	4,523,969
Share Price					$ 12.00
Number of consecutive trading days for determining the share price					20 days
Number of trading days for determining the share price					30 days
Common Class A [Member] \| Lock In Period Two [Member]
Related Party Transaction [Line Items]
Lock in period of shares held by the initial shareholders					150 days
Common Class A [Member] \| Over-Allotment Option [Member]
Related Party Transaction [Line Items]
Stock issued during the period shares new issues		1,377,622
Private Placement Warrants [Member] \| Sponsor [Member] \| Working Capital Loan [Member]
Related Party Transaction [Line Items]
Debt instrument convertible into shares amount					$ 1,500,000
Debt instrument, convertible, conversion price					$ 1.00