Using the Ground-Based Interceptor as a replacement for ALAMA?

[fredinno]

The Ground-Based Interceptor is an anti-ballistic missile operated by the US military, and based off the air-launched Pegasus Launcher. The Ground-Based Interceptor, however, is a ground launched rocket- thus, it has much less payload capacity; on the other hand, it is much more mass-produced, and available on-demand. https://en.wikipedia.org/wiki/Ground-Based_Interceptor

DARPA also pursued a ALASA rocket, which would carry 45kg optical recon sats to LEO via air-launch on existing fighter aircraft. The project was intended to launch them on-demand when required. It was cancelled when the propellant was shown to be too energetic. https://en.wikipedia.org/wiki/Airborne_Launch_Assist_Space_Access

To replace this, I propose using the Ground-based Interceptor to launch these satellites- with a HAPS upper stage from the Pegasus rocket, it can achieve polar orbits of 20-45 kg satellites. Launched from Fort Greely, Alaska (where the interceptor is deployed), it would launch into high-inclination or polar orbits- other inclinations may use a offshore pad (like Sea Launch- hell, they might be able to buy the offshore pad from them now that Zenit is almost certainly dead). Retrograde orbits are also limited, as the military will have to use a smaller 20kg optical satellite instead of the 45 kg version proposed for ALASA- or launch in a unstable low orbit (this may not be an issue, due to retrograde orbits being so uncommon anyways.)

This new LV would use 4 stages, 3 from the Ground Based interceptor, and the 4th "stage" a HAPS motor for the final orbital insertion (and accurate orbital adjustments) attached to the 45kg optical satellite.

1st stage: 1835.2 m/s
2nd stage: 3436.1 m/s
3rd stage: 4323.1 m/s
4th stage: 387 m/s

It should also launch on-demand, due to using a missile as the boost stage, though the HAPS+ Satellite combination may make this more difficult (in theory, it would be fine, HAPS is hypergolic and can be stored for long periods of time). It would also be able to be implemented rather rapidly, and allow for dedicated cubesat flights.

So is this a good idea?

[DerekL1963]

2 hours ago, fredinno said:

So is this a good idea?

 

Not really.   It's not the performance of the booster, it's the location of the launch site - it presumes 'canned' payloads that can withstand long storage or extensive additional infrastructure in a place where such things are expensive.   Plus it gives up the key reasons they looked into ALASA in the first place, the availability of a wide range of launch azimuths and the ability to fly to a launch point where the weather isn't.   (It's the wide range of azimuths that's the key, you can choose one that places a recon bird over the area of interest in the shortest possible time.)

Using an offshore pad really isn't much of an option, they're somewhat at the mercy of the weather (less than a fixed base, more than an airplane) and very expensive to maintain on 24/7 alert to get underway or to maintain underway 24/7.

A friend worked on ALASA...  his description of some of the propellant testing used a goodly number of 'colorful Anglo-Saxon monosyllables'.