Solids - friznit/Unofficial-BDB-Wiki GitHub Wiki
Background
LGM-30 Minuteman (BDB Mutineer) and Peacekeeper (also known as MX for Missile eXperimental) were originally land based ICBMs. The private launch firm Orbital Sciences Corporation subsequently developed Minotaur (BDB Pulgasari), a civilian satellite launch system using old Minuteman and Peacekeeper components.
Athena (BDB Minerva) is a purpose built solid-fuelled SLV developed by Lockheed. The Athena III proposal features a Space Shuttle Solid Rocket Booster topped by a Castor 120 with Castor 30 upper stage and OAM.
Pegasus (BDB Hippogriff) is a privately developed air-launched vehicle capable of carrying small payloads into low orbit. It is released from a carrier aircraft and its first stage wing and tail provide lift and attitude control while in the atmosphere. Minotaur-C (BDB Aldebaran), formerly known as Taurus, is based on Pegasus but uses a "zeroth" solid stage instead of an aircraft launch.
These solid-fuelled rockets have a very high TWR and will flip if not flown properly. The first stage thrust slider can be set to 75% or so to reduce dynamic pressure loads and permit more steering during ascent. All rockets require RCS turned on for roll control. It is advisable to start with the RCS of your payload disabled so it is not used during ascent.
Pitch over immediately after launch, ending at 65-75 degrees before hitting mach 1 at around 3000 metres and then following the prograde marker, keeping the angle of attack at a minimum. Hot-stage the second stage at first stage burnout. Once above 25000 metres, deviation from prograde should be safe but return to prograde during the coast phase to avoid tumbling while still in the atmosphere.
Tags: MX, Minotaur, Athena
Variants
| Launch Vehicle | First Stage | Second Stage | Third Stage | Fourth Stage | Remarks |
|---|---|---|---|---|---|
| Minuteman 3 | M-55A1 | SR-119 | SR-73 | Propulsion System Rocket Engine | |
| Minotaur I | M-55A1 | SR-119 | Orion-50XL | Orion-38 + HAPS | |
| Peacekeeper/MX | SR-118 | SR-119 | SR-120 | Post Boost Vehicle | Black paint |
| Minotaur III | SR-118 | SR-119 | SR-120 | Guidance & Control Assembly + HAPS | White paint |
| Minotaur IV | SR-118 | SR-119 | SR-120 | Guidance & Control Assembly + Orion-38/Star-48BV | White paint |
| Minotaur V | SR-118 | SR-119 | SR-120 | Star-48BV | Star-37FM Fifth Stage |
| Minotaur VI | SR-118 | SR-118 | SR-119 | SR-120 | Star-48BV Fifth Stage |
| Athena Ic | Castor 120 | Castor 30 | Orbit Adjust Module | ||
| Athena IIc | Castor 120 | Castor 120 | Castor 30 | Orbit Adjust Module | |
| Minotaur-C | Castor 120 | Orion-50ST | Orion-50XL | Orion-38 / Star-37FM | |
| Pegasus XL | Orion-50SXL | Orion-50XL | Orion-38 | Control Module + HAPS | Air Launched |
The first Athena I and II designs featured an Orbus 21D upper stage but this was later changed to the Castor 30 (technically Athena Ic & IIc)
Basic Build Guide
There are 4 primary engines that are combined to make the core stacks. They are the SR-118/Castor 120 (selectable via part variant switch), SR-119, SR-120 and Castor 30. There is also a related Castor 30XL that is not used in the canon build for any of these rockets, though it features on Antares.
Note that the SR118/Castor 120 has four variant switches. The Peacekeeper SR118, the standard Castor 120, an altitude optimized Castor 120 (suitable for ETS Carrack second stage) and the Castor 120XL. The SR118 is shorter and has slightly less solid fuel than the Castor 120, while the XL is a stretched model with slightly more fuel. The XL has not been used in any rockets to date. Each variant has its own thrust curve for different flight characteristics.
Mutineer (Minuteman)
The Minuteman III third stage is topped by a Propulsion System Rocket Engine and Avionics module below the fairing base. Minotaur I replaces the third stage with an Orion-50XL and has an Orion-38 and optional HAPS inside the fairing.
Pulgasari (Minotaur)
The Minotaur GCA has a hollow interior that can mount parts up to 0.9375m wide, such as a Star 48 or Super HAPS. There are two interior node positions, recessed and flush mount, and the variable height interstage part adds up to 0.8 meters of vertical space.
Paxus (Peacekeeper)
Peacekeeper, Minotaur and Athena each have a unique control unit that mounts below the payload fairing and provides vehicle roll control and a small engine for insertion manoeuvres or a littl extra dV. Probe cores and antennae are not included.
Minerva (Athena)
The Athena first stage Castor 120 is a civilian variant of the MX missile's SR-118. The Castor 120's are tailored to the mission, so the engine thrust slider should be set for an appropriate acceleration on the first stage and on the Athena II second stage. The Castor 30 stage uses a bell type thrust curve, with low initial thrust not reaching 100% until half fuel, then falling off again. The net effect is a slow buildup of acceleration for the first half of the burn and somewhat steady acceleration the second half.
_Kerbal Koncepts: Athena IIcS features up to 6x Orion 50SX SRB affixed to the first stage motor. The closest analogue in BDB is the Castor IV radial SRM. They do not separate and instead should be turned to have identical burn times to the Castor 120.
Hippogriff (Pegasus)
The Pegasus wing has a node for attaching to decoupler on the parent aircraft. The Control Module has a recess to house HAPS and sits on top of an Orion-38 Solid Rocket Motor inside the fairing. The Minotaur-C Control Module sits on top of the interstage and has an integrated adapter for the SRM.
Kerbal Koncepts: ETS Carrack from Eyes Turned Skyward. Up to 4x Castor 120 SRBs and topped by an Agena D under the fairing.
