curl error

Hi, when I try to get MODIS or Landsat data I get the following error:
```

Error in curl::curl_fetch_memory(url, handle = handle) : 
  Failed initialization
```

And trying to download AVHRR data gives me this error:
```
Error in open.connection(x, "rb") : 
  Timeout was reached: [www.ncei.noaa.gov] Resolving timed out after 10000 milliseconds
```

Am I doing something wrong? Thanks