Naturally, artificial aids are also necessary for tracking down some of the more distant satellites - geostationary ones for example. When trained on large objects in low Earth orbit some indication of structure can be resolved. We know of several amateurs who are constructing or using telescopes for tracking and imaging the Russian space station Mir and the shuttle, whilst in orbit. Alain Grycan and Eric Laffont from France have obtained the most spectacular amateur-made images of MIR (that we've seen). This (negative) first image is an example of their work. It appeared in Flash (the newsletter of the Belgian Working Group Satellites) in 1991. The different MIR modules are clearly visible. Also clearly discernible to the right is the Sofora mast structure. The zoom-in (at top) shows the Progress motor compartment, compared to a computer-generated drawing. Their second image was taken during the June 1995 Mir/STS-71 mission; both craft are clearly outlined.
This third image (of Mir taken in April 1991 with a 90 inch telescope) was produced by Dave Harvey at the Steward Observatory in Arizona, using the Comsoft commercial satellite tracking package on several reflecting telescopes.
Marek Kozubal and Ron Dantowitz at the Boston Museum of Science observatory are experimenting with a 12 inch reflector using the ArchImage mount to obtain images of satellites. They imaged the docked Mir/ Atlantis vehicles, producing the detailed image at left. Solar panels on Mir, the modules and the shuttle's underside are clearly visible. At this level of resolution the possibility of imaging (for example) a tumbling payload in order to directly identify its rotational axis could be possible.
Below are three pictures of the shuttle. For comparison, the picture on the extreme left was taken by a nearby released sat. The two pictures on the right are of Atlantis and were taken by the Museum of Science team at Boston on Sept 24, 1996 when the sun was still above the horizon. The picture in the middle is a raw picture and the one of the right is enhanced.
The following images were made of the tethered TiPS satellite (23937/96029F) on June 26, 1996. The image on the right is a composite of 21 frames at 10 second intervals. The non-conducting tether is 4km long and approximately 2 mm wide.
The above images of Atlantis, Mir and TiPS are courtesy of the Museum of Science, Boston.
For a taste of what has been made public of the professional work, see the images below. The left hand image was taken by a ground based telescope at the USAF Maui Optical Site (AMOS). The outline of the orbiter is clearly visible and there is a hint of detail. A similar image (shot from the SPAS pallet satellite during STS-7 in 1983, at a range of a few hundred meters) is alongside on the right.
This image is a frame from a video sequence taken using a CCD camera and a 48 inch telescope at the USAF Phillips Lab Malabar Test Facility at Valkaria, Florida during STS-37.
There is an interesting web-page by Timothy Schulz on the subject of "Blind Deconvolution for Astronomical and Space-Object Imaging".
Allen Thomson on SeeSat-L provides a couple of links on the topic of speckle-imaging techniques for observing satellites from earth.
Possibly the most spectacular telescopic observations of any satellite were those rumored to have been made of the space shuttle Columbia during STS-1, by an orbiting Keyhole reconnaissance satellite. Supposedly to allay fears concerning detached thermal protection tiles on the underside of the orbiter (crucial in determining whether the vehicle would survive the heat of re-entry), the orbiting Keyhole was used to examine the belly of Columbia after tiles were noticed to be missing from the OMS pods at the rear of the craft. Subsequent analysis of the orbits of the shuttle and the known Keyhole satellites in orbit at the time of the mission indicates several possible photo opportunities. The tragic loss of Columbia and her crew on STS 107 renewed interest in the possibility of Keyhole imaging.
Another source reports that surveillance of STS-1 was made by USAF ground based telescope, specifically at the USAF missle tracking annex in Valkaria, Florida (just south of Melbourne) by their 48" satellite imaging telescope. The photos were accidently released to the press after the NRO had turned them over to NASA for analysis. Subsequently, they were aired on a Saturday morning news program, but were very quickly pulled.
It is debatable as to whether use of a suitable image restoration technique could reclaim sufficient resolution so as to identify individual tiles or groups of them. In any event we are unlikely to see such pictures if they exist for many years yet, if at all.
Gorden Garradd from Loomberah NSW, Australia (151.04E/31.33S,alt. 845m), took this photo, believed to be the Cassini/Huygens probe (upper left track) and the Titan IV Centaur booster (lower right track) venting hydrogen or oxygen after separation. At this point the objects are no longer in Earth orbit but in a heliocentric orbit on a path to an encounter with Venus. The arrow points to star PPM 204332 (mag 8.8) at Ra 20h41m34s, Dec -8.8 deg.
An enlargement (318k) more clearly shows a cloud formation around the lower right object. The range to the objects is approximately 26000 km.
The photo was taken with a 25cm f/4.1 Newtonian. The exposure was 17 seconds ending at 11:02:00 UT on Oct 15, 1997 using hypered Kodak Gold III 400 ISO. Limiting stellar magnitude is 15.0. Launch of the Cassini probe took place on Oct 15, 1997 at 08:43 UT.
Bill Keel has an excellent compilation of photos resulting from amateur and professional Telescopic Tracking of the Apollo Lunar Missions.
SeeSat-L subscriber Thom Troszak reports on photographing Mir with his 8" reflector telescope and provides a link to his and other's photos.
SeeSat-L subscriber Josef Huber has produced stills and videos of ISS, Mir and the shuttle.
Mike Tyrrell and Philip Masding provide analysis of pictures taken of the ISS using virtual-reality simulations of the ISS (as reported on SeeSat-L).
Links: to the VSO Home Page, the observing guide, and satellite predictions.