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The next, and the major, milestone for the mission is to find interference fringes. This is critical to operating the spacecraft as part of a high-resolution telescope.
Interference fringes arise from the wave nature of light. When superimposed, two wave trains cancel or reinforce. Beats between two very close notes, in music, is an example of this: where the waves are in phase they produce a strong note, and when out of phase they produce silence. For light, when two wave trains of the same frequency traveling in slightly different directions meet at a screen, they produce alternating bands of bright and dark, where the waves are in phase and out of phase, respectively. Those bands might look like the fringe on the edge of a piece of fabric -- so they are called "fringes".
Light -- and many other waves such as ocean waves -- always take the fastest path. Transparent, refracting materials such as glass slow light down. Light will bend, so as to spend less time in the slower material: even though the overall path has greater length, travel time is less. It's kind of like flying from Los Angeles to Washington DC, and then driving to Gaithersburg MD: even though you retrace part of the your path, it's far faster than driving the direct route all the way!
Interference is responsible for the ability of a lens to focus light. Refraction by the glass of the lens bends the light, so that waves from all points over the surface of the lens reinforce at the focus, and cancel elsewhere. In effect, the lens acts as a circular analog computer to form the image. Lenses are very cool in this way.
Radio waves can easily be recorded and played back using video recorders -- so the process of aligning the phases along different paths can be done by recording signals at different points, then playing them back so that they combine with exactly the correct lag. This used to be done by aligning video tapes with exactly the right offset. Nowadays, it's done by reading the data streams from the hard disk of a computer with exactly the right lag, as in a solid-state DVR.
The trick is to find exactly the right lag. That requires knowledge of the exact positions of all the radio telescopes used for the experiment. That requires knowledge of their positions to a fraction of a radio wavelength: a few cm. Or, you can perform a search of all possible positions, look for the appearance of interference, and then know the positions to that accuracy. This allows the measurement of distances between radio telescopes to a few cm, and demonstration that the continents are still drifting today. GPS works via a closely related principle: but instead of one source and many radio telescopes, it has many sources (the GPS satellites) and one (tiny) radio telescope inside the receiver.
Finding the exact position of the Radioastron satellite will be harder. Space is big and Radioastron moves fast. Various techniques are being used to track the satellite, including optical telescopes, radio delay-Doppler ranging, and laser ranging; but the test will be to find that first interference fringe on some astrophysical source. Then the scientific work can begin.
Here is my place of work in Moscow, near the Kaluzhskaya subway station. This building houses the Astro Space Center, as well as some other labs and offices. It was originally built to house chemistry research, and every other floor is a "technical floor", designed to house chemistry labs, with the narrow windows; the intermediate floors are "office floors", with the higher windows. The two categories are numbered separately, making navigation confusing.The window of the office where I work is on the uppermost office floor about halfway along the building.
We watched the launch from about 3 km away. Activity around the rocket, and vapor from the liquid-oxygen tanks, was easily visible. The burn began on schedule to the second. Flames erupted from the base of the rocket, then a large cloud of exhaust formed. The rocket lifted off quickly and sped up into the sky. I wasn't able to resist shouting "It's a bird!", which (my father told me 45 years ago) is what rocket engineers say when their creations leave the Earth. 7 seconds after ignition, we heard an earth-shaking rumble, punctuated by sharp cracks, as sound from the site finally reached us. The rocket tilted quickly, shed its first stage and proceeded to orbit.
The rocket is the new Zenith-2. This was characterized as an "eco-rocket" -- its fuel is kerosene and oxygen, much less toxic than the hydrazine used by the earlier Proton and Soyuz rockets. It has a slimmer profile, without the flaring strap-on boosters that made those look so Russian.
Russia assembles its rockets in a horizontal position, and carries them to the pad by rail, on cars equipped with special hydraulic cradles. At the pad, the cradle rotates and lifts the rocket into a vertical position, and holds it there during fueling. During the countdown the cradle drops back to the car, and the rocket supports itself: this seems precarious, but the forces are small compared with the G-forces during acceleration. Piloted by a very brave crew, the train pulls away from the rocket 4 min before liftoff.
The orbit was modified from a circular orbit a few hundred km above the earth, to an ellipse reaching nearly to the Moon, by the Frigat booster. This took place in the southern hemisphere, out of contact with Russian tracking stations; it must have been somewhat nerve-wracking for the controllers. In the event the burn worked perfectly, and only a couple of hours after the launch the spacecraft was on its final orbit; and we were eating lunch at the "Hunter's Cottage" in Baikonur.
Launching a space mission must be somewhat like raising a child. You work for 25 years, providing the best preparation you can imagine and afford; and then you launch this precious creation into a region of unknown dangers where you have little control. Differences include the fact that work on a spacecraft actually involves 8 hours of work a day, for which you are paid; and children can be called back for modification.
Baikonur was a city on the silk road: the trade route that carried silk from China to Europe before the Europeans discovered sea routes in the 14th century. This Sunday market in a park in Baikonur had many buyers and sellers who looked like they would have fit right in with Marco Polo, with slight changes in clothing and products. The market seemed well organized and closely supervised, with the sellers wearing special badges and stalls segregated by product.
These young ladies sold me a cup of kvas, a traditional Russian beverage made from bread. It's great in hot weather! They said that they didn't want their picture taken, but laughed hard enough to make me think that they didn't mind. One seemed to be making a few photos of me, in any case.
Here I am enjoying a cup of kvass.
The area around Baikonur is famous for melons. We enjoyed them at breakfast. Many people took melons back to Moscow.
The lady on the left sold me a bunch of grapes. They were very sweet: delicious! Her friend worked in the next stall, also selling fruit.
Not everyone was happy to be photographed. I bought a sun hat from an older lady. When I trotted out my Russian phrase to ask if I could photograph her, she who responded "Nyet, nyet, nyet". She seemed upset and unhappy. Perhaps she had not been just a hat seller, before the Soviet Union collapsed. I hoped that she had not lost a son or husband in the Soviet war in Afghanistan.
A pair of young women in white coats inspected the market for hygiene. They asked my name and nationality -- giving me a chance to use some phrases from memorized dialogs -- and expressed amazement when I said "Amerikanski". My claim to be from Santa Barbara was clearly far beyond belief. (Almost all Russians are familiar with Santa Barbara from the soap opera, which was a big hit here after it ended in the US.) This pair wouldn't pose for a picture, perhaps fearing that it would be unprofessional.
This young lady sold me a pair of sunglasses. She ran the shop with another girl; they seemed to do excellent business.
This young man sold me a plate of pilaf for lunch. It was delicious, particularly with a cold beer. He cooked it in this brazier, made from a recycled oil drum. Somehow he kept his clothing spotless.
We moved to a different hotel in Baikonur: older, with in-room air conditioners instead of central air, smaller rooms, smaller beds -- but closer to the center of town and restaurants, and costing about 1/4 as much per day. It also has in-room internet access, so I no longer need to sit in the lobby and rely on a contractor to share a password.
The banner out front marks the 50th anniversary of Gagarin's flight: the first orbit of the Earth by a human being. On the steps are Norbert Bartel from York University in Canada and Leonid Gurwitz from Delft University and JIVE in the Netherlands (JIVE is Joint Institute for VLBI in Europe -- VLBI stands for Very Long Baseline Interferometry). Leonid trained as a cosmonaut and has a lot of interesting stories and perspectives on Baikonur and the Russian space program.
In front of the hotel is a large square, formerly a parade ground, dominated by a statue of Vladimir Lenin. Baikonur was, of course, originally a military site, devoted to development of ICBMs. Women were forbidden. When a few women arrived to work as nurses and clerks, the social life picked up; famously, all soldiers were ordered to take dancing lessons. Behind the statue of Lenin is an officer's club, often used as a theater, but now empty.
Last night the international scientists attending the launch had dinner with Vladimir Popovkin, Deputy Defense Minister and the Director General of the Russian Space Agency. He is the top official in charge of all Russian space programs, manned and unmanned, civilian and military. He's attending to his work here at Baikonur, and very kindly took the opportunity of our presence to invite us to dinner. Also attending were the Director of the Lavochkin Association, and Academician Nikolai Kardashev, the Director of the Astro Space Institute of the Lebedeev Institute of the Russian Academy of Sciences.
I found Director General Popovkin to be unusually thoughtful and engaged. He started the dinner by observing that he had many chances to talk with Russian scientists about future directions for their space program, and he was very curious to hear our opinions, as visitors from overseas, as to the best directions for future Russian scientific missions, and the properties of Russia that made those the best. Our answers took the form of toasts, as is traditional at Russian dinners. He listened to our responses, and his toasts, in turn, indicated that he'd thought carefully about them.
My own toast included the observation that Russia has a long tradition of strength in theoretical physics. I ascribe this, in part, to their excellent educational system. I suggested that the papers of Kardashev, for example, have remained classics because they take theory as their compass. Thus, I proposed a toast to the theorists.
Deputy Minister Popovkin very kindly agreed to be photographed with me, and the image is below. Because I brought only one set of clothes to Baikonur, I am not particularly well dressed; but as one of our Russian hosts told me, not much is expected of an American.
Here is a Buran, the Soviet-era reusable space vehicle, similar to the shuttle, at the Baikonur space museum. It is slightly larger than the shuttle, and was launched on a larger rocket. It flew once in space, without human crew, as a test -- before the economic crisis attending the collapse of the Soviet Union ended the program. Actually ten were built, so this is not unique.
Here I am at the controls. This is the copilot seat.
Today we visited the museum of of Russian space flight at Baikonur. It's an impressive record of an active industry, dating back to before Sputnik and stretching to today. This involved a trip to the site to "plakata 0" where the original builders of the site stayed. This small cottage was used by Korolev, the first Chief Designer. A nearly identical cottage next door was used by Gagarin and his backup in the days before his historic flight.