Only Fossett is flying solo on the estimated two to three week trip. In addition, three other teams have announced their plans to join the race, including a team who will make their attempt from Australia, ascending to an altitude of 130,000 feet.
ALS is a fatal disease: Most ALS patients die within two to five years of diagnosis. Common causes of death are respiratory failure and/or cardiac problems related to insufficient oxygen. Patients may also suffer respiratory infections, such as pneumonia.
Researchers still don't know exactly what causes motor neurons to die with ALS. Gene changes, or mutations, are behind 5% to 10% of ALS cases. More than 12 different gene changes have been linked to ALS. One change is to a gene that makes a protein called SOD1.