Nigeria's multi-million dollar communication satellite is spinning out of control just 18 months after launch. The Chinese built Nigcomsat at a cost to Nigeria of $340 million. It was expected to provide broadband Internet and communications for government agencies. The government says the situation is under control and the satellite is only experiencing power problems. Critics say the device was a white elephant project that was hurriedly executed by former president Olusegun Obasanjo.

Paul Ceruzzi is curator of the Smithsonian National Air and Space Museum. He talked with VOA English to Africa reporter Chinedu Offor about what could be wrong with the Nigerian satellite.

 "(The) satellite, once it is placed in orbit, has to be managed so that it points in the right direction, just like driving a car down the road. The antennas have to point to the ground, the solar panels have to point to the sun and they (must) have fuel on board (that) powers tiny rockets that do that or other means of stabilizing it. But sometimes they run out of fuel or Sat system breaks down.  Then it stays there in orbit and begins to tumble, if it loses contact with the solar panels or (they are) no longer pointing at the sun, then it losses electrical power. If the antennas are no longer pointing at the ground, then there is no way to communicate with it. So it becomes kind of dangerous piece of junk flying at 17,000 miles an hour; it can be a serious problem."

Ceruzzi says it is unusual for new satellites to fail. "In the early days of the space program things like that happened a lot, actually, unfortunately, but over the years they have gotten more reliable, but it does happen. It has happened from time to time and the other issue of course is that all satellites, eventually run out of fuel and they potentially can have the same fate unless people do things to actively manage them for that day. But for something to fail so soon after launch is rare today but it does happen".

Ceruzzi says it is difficult to have an advance warnings of the precise location where a satellite might come down. Scientists may have such a warning "only in the few hours or so before it actually comes down. It could stay up there for months or years even and then atmospheric drag will slowly bring it out of orbit. And then, only at the very last moment, do you really know where it is going to hit."