Minotaur IV

Cost per launch$50 million ^[1]SizeHeight23.88 metres (78.3 ft)Diameter2.34 metres (7 ft 8 in)Mass86,300 kgStages4Capacity Payload to LEOMass1735 kg (28.5°, 185 km) Associated rocketsFamilyMinotaurDerivative workMinotaur VLaunch historyStatusActiveLaunch sitesVandenberg AFB, SLC-8
MARS, LP-0B
PSCA, LP-1
CCAFS, SLC-46Total launches7Success(es)7First flight22 April 2010Last flight15 July 2020First stage – SR-118Powered by1 SolidMaximum thrust2,200 kilonewtons (490,000 lb_f)PropellantSolidSecond stage – SR-119Powered by1 SolidMaximum thrust1,365 kilonewtons (307,000 lb_f)Burn time54 secondsPropellantSolidThird stage – SR-120Powered by1 SolidMaximum thrust329 kilonewtons (74,000 lb_f)Burn time62 secondsPropellantSolidFourth stage (Baseline) – Orion 38Powered by1 SolidMaximum thrust32.2 kilonewtons (7,200 lb_f)Burn time67.7 secondsPropellantSolidFourth stage (Optional) – Star-48VPowered by1 SolidMaximum thrust68.6 kilonewtons (15,400 lb_f)Burn time84.1 secondsPropellantSolid

Minotaur IV, also known as Peacekeeper SLV and OSP-2 PK is an active expendable launch system derived from the LGM-118 Peacekeeper ICBM. It is operated by Northrop Grumman Space Systems, and made its maiden flight on 22 April 2010, carrying the HTV-2a Hypersonic Test Vehicle.^[2][3][4] The first orbital launch occurred on 26 September 2010 with the SBSS satellite for the United States Air Force.

The Minotaur IV vehicle consists of four stages and is capable of placing 1,735 kilograms (3,825 lb) of payload into a Low Earth orbit (LEO).^[5][6] It uses the first three stages of the Peacekeeper missile, combined with a new upper stage. On the baseline version, the fourth stage is an Orion 38. However a higher performance variant, designated Minotaur IV+, uses a Star-48V instead. A three-stage configuration (no Orion 38), designated the Minotaur IV Lite, is available for suborbital trajectories. The Minotaur IV has also been flown with multiple upper stages. A five-stage derivative, the Minotaur V, made its maiden flight on 7 September 2013.

Minotaur IV launches are conducted from SLC-8 at Vandenberg Air Force Base, LP-0B at the Mid-Atlantic Regional Spaceport, SLC-46 at Cape Canaveral Air Force Station and Pacific Spaceport Complex – Alaska Pad 1 of the Pacific Spaceport Complex – Alaska (PSCA).

Launch history

Flight No.	Date/Time (UTC)	Variant	Launch Site	Payload	Trajectory	Outcome	Remarks
1	22 April 2010 23:00	Minotaur IV Lite	Vandenberg, SLC-8	HTV-2a	Suborbital	Success	Successful launch, but payload failed
2	26 September 2010[7] 04:41	Minotaur IV	Vandenberg, SLC-8	SBSS	SSO	Success
3	20 November 2010 01:25[7]	Minotaur IV HAPS	Kodiak, LP-1	STPSAT-2 FASTRAC-A FASTRAC-B FalconSat-5 FASTSAT O/OREOS RAX NanoSail-D2	LEO	Success	STP-S26 launch. Included a Hydrazine Auxiliary Propulsion System (HAPS) to take the vehicle to a secondary orbit after placing payloads into the primary orbit.
4	11 August 2011 14:45[8]	Minotaur IV Lite	Vandenberg, SLC-8	HTV-2b	Suborbital	Success	Successful launch, but payload failed
5	27 September 2011 15:49	Minotaur IV+	Kodiak, LP-1	TacSat-4	LEO	Success	First Minotaur IV+ launch
6	26 August 2017 06:04	Minotaur IV / Orion 38	CCAFS, SLC-46	ORS-5	LEO[9]	Success	Ran in a 5-stage configuration, using an extra Orion 38 motor to put ORS-5 in to an equatorial orbit.
7	15 July 2020 13:46[10]	Minotaur IV / Orion 38	MARS, LP-0B	NROL-129	LEO[9]	Success	Carried four payloads (USA-305 to USA-308). First NRO launch on a Minotaur IV and first from Virginia's Space Coast.[11]

Planned launches

Date/Time (UTC)	Variant	Launch Site	Payload	Trajectory	Remarks
April 2024[12]	Minotaur IV	Vandenberg, SLC-8	NROL-174	LEO
September 2024[13]	Minotaur IV		?	LEO	STP-S29A mission
May 2025[14]	Minotaur IV	Vandenberg, SLC-8	EWS-I 1	LEO	USSF-261S-A mission
TBD	Minotaur IV Lite	Vandenberg, SLC-8	CSM	Suborbital
TBD	Minotaur IV		?	LEO	ORS mission
TBD	Minotaur IV		?	LEO	ORS mission

STP-S26

The third Minotaur IV launch, which was also known as STP-S26, deployed eight payloads. It was the 29th small launch vehicle mission in STP's 49-year history of flying DoD space experiments,^[15] STP-S26 was intended to extend previous standard interface development efforts, implementing a number of capabilities aimed at enabling responsive access to space for small experimental satellites and payloads. STP-S96 launched at 01:25 UTC on 20 November 2019 from the Kodiak Launch Complex. The launch facility contractor was Alaska Aerospace Corporation (AAC). The payloads were released in a 650 kilometres (400 mi) orbit, before the HAPS upper stage was demonstrated by deploying two ballast payloads into a 1,200 kilometres (750 mi) orbit.

The primary objective of the STP-S26 launch was to deploy STPSAT-2 (USA-287), whilst demonstrating the ability of the Minotaur IV to carry additional payloads, by deploying FASTSAT, FASTRAC, RAX, O/OREOS and FalconSat-5. A Hydrazine Auxiliary Propulsion System upper stage was flown aboard the Minotaur to demonstrate its ability to deploy payloads to multiple orbits, however only mass simulators were deployed after the HAPS burn.

The launch marked the first flight of an STP-SIV (Standard Interface Vehicle) satellite, the first use of the Multi Mission Satellite Operations Center Ground System Architecture (MMSOC GSA), the first flight of the Minotaur IV's Multi-payload Adapter (MPA), the first use of a HAPS to obtain multiple orbits on a Minotaur IV flight, the first Minotaur launch from Kodiak Launch Complex (KLC), and the first deployment of CubeSats from a Minotaur IV via Poly-PicoSatellite Orbital Deployers (P-Pods).^[15]

See also

• Comparison of orbital launchers families
• Comparison of orbital launch systems

References

External links

• FASTRAC Ready To Go Into Space
• Alaskan Aerospace Corp official website