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LIVE: Orbital Pegasus XL/NuSTAR - June 13, 2012
by
Kim Keller
on 30 Nov, 2011 18:00
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The Pegasus XL vehicle M48 is being integrated at VAFB right now. Orbital will be performing a milestone test, Vehicle Verification, today. I've taken off my Atlas hat, flown to VAFB, and put on my Pegasus headgear. I got my first look at the vehicle this morning and I'll be covering the test this afternoon. Launch is set for early spring from Kwajalein.
http://science.nasa.gov/missions/nustar/
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#1
by
Kim Keller
on 30 Nov, 2011 23:19
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Good test today. We verified avionics connections and functionality of the fin actuator system, the stage 2 & 3 TVC actuators and the RCS jets.
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#2
by
Mr. D
on 01 Dec, 2011 00:59
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The Pegasus XL vehicle M48 is being integrated at VAFB right now. Orbital will be performing a milestone test, Vehicle Verification, today. I've taken off my Atlas hat, flown to VAFB, and put on my Pegasus headgear. I got my first look at the vehicle this morning and I'll be covering the test this afternoon. Launch is set for early spring from Kwajalein.
http://science.nasa.gov/missions/nustar/
Wow, the spacecraft rendering on that page is positively antique!
See
www.nustar.caltech.edu for the actual spacecraft...
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#3
by
Fequalsma
on 02 Dec, 2011 02:55
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Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
The "antique" version on the NASA page is the Phase A/B configuration, with 3 telescopes and detectors, and 2 solar arrays. Do you know what caused the down-scope to 2 t/d's shown on the JPL website?
http://science.nasa.gov/missions/nustar/
Wow, the spacecraft rendering on that page is positively antique!
See www.nustar.caltech.edu for the actual spacecraft...
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#4
by
Jim
on 02 Dec, 2011 10:41
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Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
Your point is meaningless. The project does not get to pick the launch vehicle. Yes, they were Pegasus class does not mean it is going to fly on Pegasus. Falcon 1 had a shot at this.
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#5
by
Jim
on 02 Dec, 2011 10:42
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Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
The "antique" version on the NASA page is the Phase A/B configuration, with 3 telescopes and detectors, and 2 solar arrays. Do you know what caused the down-scope to 2 t/d's shown on the JPL website?
Flying on a Pegasus.
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#6
by
Ronsmytheiii
on 02 Dec, 2011 13:13
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#7
by
Mr. D
on 03 Dec, 2011 21:09
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Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
Huh?
The LV contract was announced on 9 Feb 2009?.
Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
The "antique" version on the NASA page is the Phase A/B configuration, with 3 telescopes and detectors, and 2 solar arrays. Do you know what caused the down-scope to 2 t/d's shown on the JPL website?
Flying on a Pegasus.
Looking at the specs for a F1 launch to 500 km, the payload would only have been ~350 kg (and to a significantly worse orbit, ideally you'd launch it to 0 inclination with an altitude of 550-650 km). NuSTAR, as built, weights in at 380 kg
(in Table 2). So, it doesn't look like launching on a Pegasus has anything to do with the move from 3->2 mirrors. More like mass constraints.
GEMS had the exact same thing happen.
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#8
by
Jim
on 03 Dec, 2011 22:45
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Mass constraints due to launching on a Pegasus
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#9
by
Mr. D
on 03 Dec, 2011 23:09
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Mass constraints due to launching on a Pegasus
I'm not saying that this is not the case, only that the the publicly documented performance of F1 (
as per figure 2-4) would make it even more mass constrained then a Pegasus XL. And could not have launched the actual NuSTAR that is being launched on an actual Pegasus XL.
Unless the F1e was being considered back in late 2008/early 2009? Or the documentation published by NuSTAR's PI is inaccurate on mass/altitude somehow. Or perhaps you have some tasty details you would like to share? Oh, common, you know you want to tell.
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#10
by
William Graham
on 04 Dec, 2011 07:26
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Mass constraints due to launching on a Pegasus
I'm not saying that this is not the case, only that the the publicly documented performance of F1 (as per figure 2-4) would make it even more mass constrained then a Pegasus XL. And could not have launched the actual NuSTAR that is being launched on an actual Pegasus XL.
Unless the F1e was being considered back in late 2008/early 2009? Or the documentation published by NuSTAR's PI is inaccurate on mass/altitude somehow. Or perhaps you have some tasty details you would like to share? Oh, common, you know you want to tell.
Falcon 1 and Pegasus are not the only rockets available. Taurus, for example, can put up to 1,450 kilograms into LEO.
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#11
by
as58
on 04 Dec, 2011 08:53
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Wasn't NuSTAR cancelled at some point? I thought they had to do some descoping the get the mission reinstated.
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#12
by
Mr. D
on 04 Dec, 2011 14:08
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Mass constraints due to launching on a Pegasus
I'm not saying that this is not the case, only that the the publicly documented performance of F1 (as per figure 2-4) would make it even more mass constrained then a Pegasus XL. And could not have launched the actual NuSTAR that is being launched on an actual Pegasus XL.
Unless the F1e was being considered back in late 2008/early 2009? Or the documentation published by NuSTAR's PI is inaccurate on mass/altitude somehow. Or perhaps you have some tasty details you would like to share? Oh, common, you know you want to tell.
Falcon 1 and Pegasus are not the only rockets available. Taurus, for example, can put up to 1,450 kilograms into LEO.
Unless OSC's got an equatorial site somewhere, that's not a particularily enticing option. That's because the particle background at any elevation greater than ~10 degrees is just awful. See
Figure K1 (page 50) for an illustration. So, even though you could have brought more telescopes, the mission would have been
less sensitive (given that sensitivity goes as the square root of background divided by effective area) unless the launcher is big enough to do a dogleg maneuver to < 10 degrees. From
figure 9 of this paper, it seems that you'd need a Falcon 9 to get even the reduced NuSTAR there from the continental US. Never mind that this is quite bigger than a Taurus and any of the Minotaurs.
Wasn't NuSTAR cancelled at some point? I thought they had to do some descoping the get the mission reinstated.
Yea, it was canned from February 2006 to September 2007. But the incremental cost of additionnal telescopes is quite low. At the end, they were pumping out ~200 good mirror segments per week, and that's about 10 weeks per mirror assembly. Very tightly nested X-ray mirrors are a very different beast than optical telescopes (or Chandra style mirrors) in that even small mirrors get into the mass production regime.
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#13
by
William Graham
on 04 Dec, 2011 15:28
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Unless OSC's got an equatorial site somewhere, that's not a particularily enticing option. That's because the particle background at any elevation greater than ~10 degrees is just awful. See Figure K1 (page 50) for an illustration. So, even though you could have brought more telescopes, the mission would have been less sensitive (given that sensitivity goes as the square root of background divided by effective area) unless the launcher is big enough to do a dogleg maneuver to < 10 degrees. From figure 9 of this paper, it seems that you'd need a Falcon 9 to get even the reduced NuSTAR there from the continental US. Never mind that this is quite bigger than a Taurus and any of the Minotaurs.
Fair enough. I wasn't aware of the constraint on inclination.
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#14
by
Prober
on 04 Dec, 2011 16:58
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Looking forward to seeing this fly! Gee - they're launching on a Pegasus. Who knew?
Your point is meaningless. The project does not get to pick the launch vehicle. Yes, they were Pegasus class does not mean it is going to fly on Pegasus. Falcon 1 had a shot at this.
Yes I remember you posting that SpaceX didn't bid on this.
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#15
by
Jason1701
on 04 Dec, 2011 22:32
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Mass constraints due to launching on a Pegasus
I'm not saying that this is not the case, only that the the publicly documented performance of F1 (as per figure 2-4) would make it even more mass constrained then a Pegasus XL. And could not have launched the actual NuSTAR that is being launched on an actual Pegasus XL.
Unless the F1e was being considered back in late 2008/early 2009? Or the documentation published by NuSTAR's PI is inaccurate on mass/altitude somehow. Or perhaps you have some tasty details you would like to share? Oh, common, you know you want to tell.
Falcon 1 and Pegasus are not the only rockets available. Taurus, for example, can put up to 1,450 kilograms into LEO.
And Taurus is in a long time-out for NASA science missions.
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#16
by
simonbp
on 04 Dec, 2011 23:16
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Your point is meaningless.
Somewhat; Pegasus has much tighter faring restrictions that ground-launched rockets, which can seriously affect the amount of science you get out of a space telescope. GALEX, for example, ended up with a smaller aperture than they could have fit in the budget. It the aperture restrictions were too great, then they've have to bumped up to Taurus, with according cost increases.
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#17
by
Kim Keller
on 05 Dec, 2011 00:31
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Orbital completed a successful "phasing" test on Thursday. The purpose of the test is to verify the correct response of the fin system, the stage 2 & 3 TVCs and the RCS jets to manual rotation of the vehicle's SIGI, part of the rocket's autopilot/navigator. The manual rotation simulates vehicle flight motions. As the SIGI is rotated the motion of the fins and rocket nozzles in response to the motion is recorded and analyzed. Each stage is done in turn, with the RCS thrusters rounding out the test.
Build-up of the vehicle continues. The rocket is actually assembled on-site in a Vandenberg assembly building. It's not like the way in which Atlas or Delta stages are shipped to the launch site for final test and integration. Orbital's method is to receive basic rocket motors from ATK, and build up a Pegasus vehicle from those basic building blocks. All the bits and pieces are attached, bonded, bolted, RTV'ed, etc.
If the schedule holds we'll do the first of several flight simulations next week which replicates a basic Pegasus mission, exercising all the vehicle's systems.
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#18
by
Kim Keller
on 22 Dec, 2011 16:06
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Orbital ran a successful flight simulation this month, running through a generic mission sequence that exercises most of the rocket's systems. It was cool watching the fin sweeps just before simulated drop, then watching them smoothly rotate during first stage "flight". The end-of-mission RCS blowdown sounded like a machine gun battle as the cold gas jets released nitrogen in brief pulses.
Mating of stages 1, 2 & 3 will occur early next month, followed by another flight simulation. NuSTAR itself will arrive late in January.
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#19
by
Robotbeat
on 22 Dec, 2011 16:11
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Cool.

Do you have video?