Spitzer Space Telescope

 2003-038A

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360 l of LHeI (about 45 kg?)

The SIRTF 0.85-meter Space Infrared Telescope Facility will be managed by JPL for NASA. It is built by Lockheed Martin/Sunnyvale with the cryogenic telescope built by Ball Aerospace. SIRTF will be launched by Delta into solar orbit. Orbit is 371.9d, 0.992 x 1.032 AU x 1.14 deg (Sun center)

0.988 x 1.028 if minus Rsun: enter to O S 147700000 x 153680000 x 1.1 VP = 30.194 VA = 29.024

Escape vel at 200 km is sqrt 121.19

On Aug 25 0600, Earth is at 0.8892 -0.4411 -0.1912 0.008428 0.01353 0.005868 (J2000). Earth orbit has VP = 30.208 VA = 29.220 Current vel 0.01699 AU/d = 29.41 radius = 1.0108 Vinf = (220, 108, 580) to get to tabulated orbit Means V = 629m/s, C3 = 0.40 km2/s2.

* W Sun 1 27827U 03027A 3237.25000000 0.00000000 +00000-0 +00000-0 0 14 2 27827 0.0069 315.8962 0274081 253.5337119.4841 km 149125106.15 Earth pos * W Sun 1 27827U 03027A 3237.25000000 0.00000000 +00000-0 +00000-0 0 14 2 27827 1.1282 331.5068 0199224 272.2777 85.5373 km 151394779.06 Guess at SIRTF orbit

After 2.6 years in a trailing solar orbit SIRTF will be 0.32 AU from Earth. (48 M km)

Launch mass is 923.5 kg.

Total dry mass 851 kg. Cover 6 kg 50.4 kg He, 15.6 kg N2.

Octagonal spacecraft bus, telescope assembly, solar panel assembly.

The telescope is launched warm with only the instrument package inside the cryogenic dewar. The optics are cooled on orbit to around 5K by radiation and contact with the cryo boiling off from the dewar. The instruments remain at less than 2K.

The IRAC camera has a set of 256 x 256 pixel arrays with a 5 arcmin field of view, imaging at 3.5, 4.5, 6.3 and 8.0 microns.

The IRS has a moderate (R=600) resolution 10-20 and 20-40 micron channel, and a long slit (R=50) channel covering 5 to 40 microns. It makes observations following on from ISO's SWS instrument.

The MIPS is a longer wavelength imager (see table). It also has R=20 low res spectroscopy in the 50-100 micron range, following up ISO's LWS instrument.

Full Height: 4.45 m

CTA Height: 2.59 m

Solar Shield Height: 4.32 m

Full Depth: 2.11 m (measured from solar shield to spacecraft front)

After launch, the star tracker failed to acquire and Spitzer entered safemode from T+1h26m to T+14h40m.

SIRTF
Date	Time	Event	Orbit
2003 Aug 25	0535:39.2	Launch by Delta 7920H	CC SLC17B
		T+1:15 SRM 1-6 out
		T+1:19 SRM 7-9 on
		T+1:22 SRM 1-6 sep
		T+2:35 SRM 7-9 out
		T+2:40 SRM 7-9 sep
		T+4:24 Stage 1 MECO
		T+4:34 Stage 1 sep
		T+4:39 SES-1
		T+4:44 Fairing
	0542	T+7:17 SECO-1	166 x 167 x 31.5
	0613	T+40:25s SES-2
	0618	T+45:06 SECO-2	170 x -1987709 x 31.6
	0623	T+50:00s Stage 2 sep	172 x -2084426 x 31.5
		C3 = 0.393 DRA 310.98, 31.47
		T+1:05:23 SES-3
	0640	T+1:05:29 SECO-3
		T+4110s (Delta)	2065 x -300891 x 31
		T+1:11:43 SES-4
	0647	T+1:11:49 SECO-4
2003 Aug 25	1625	Delta Pass EL1:4
2003 Aug 25	1908	Pass EL1:4
2003 Aug 30	0219	Dust cover eject
2003 Aug 31	1110?	Delta depart Earth sphere 1.5Mkm
2003 Aug 31		Aperture door open (prior to 0230Z)
2003 Sep 7	1605	Depart Earth sphere 1.5Mkm
2003 Nov 15	2100	2P/Encke closest approach at 33.59Mkm
2009 May 15	2211	LHe depleted, standby mode
2009 May 15		Begin warm mission

Payload:

• IRS Infrared Spectrometer

• IRAC IR Array Camera (Fazio)

• MIPS Multiband Imaging Photometer

• Cryogenic dewar

• 0.85-m telescope

• 1.5m antenna