diff --git a/simple/utils/spectra_convert.py b/simple/utils/spectra_convert.py
index 718b8e631..7b38fa5eb 100644
--- a/simple/utils/spectra_convert.py
+++ b/simple/utils/spectra_convert.py
@@ -10,56 +10,16 @@
 logger = logging.getLogger("SIMPLE")
 
 
-def convert_to_fits(spectrum_info_all, spectrum_table, header):
-    # TODO: add docstring with expected keywords
-    # TODO: add error handling for expected keywords
+def compile_header(wavelength_data, **original_header_dict):
+    """Creates a header from a dictionary of values.
 
-    object_name = header["OBJECT"]
-
-    header["HISTORY"] = "File made with the SIMPLE convert_to_fits.py function"
+    wavelength_data: an array of wavelengths
 
-    wavelength = spectrum_table["wavelength"]
-    flux = spectrum_table["flux"]
-    flux_unc = spectrum_table["flux_uncertainty"]
+    original_header_dict: a dictionary of values to be included in the header
 
-    # header = compile_header(wavelength, **spectrum_info_all)
-
-    spectrum_data_out = Table(
-        {
-            "wavelength": wavelength * u.um,
-            "flux": flux * u.Jy,
-            "flux_uncertainty": flux_unc * u.Jy,
-        }
-    )
+    Returns: a fits header dictionary
 
-    # Make the HDUs
-    hdu1 = fits.BinTableHDU(data=spectrum_data_out)
-    hdu1.header["EXTNAME"] = "SPECTRUM"
-    hdu1.header.set("OBJECT", object_name, "Object Name")
-    hdu0 = fits.PrimaryHDU(header=header)
-
-    # Write the MEF with the header and the data
-    spectrum_mef = fits.HDUList([hdu0, hdu1])  # hdu0 is header and hdu1 is data
-
-    fits_filename = (
-        spectrum_info_all["fits_data_dir"]
-        + object_name
-        + "_"
-        + header["DATE-OBS"]
-        + ".fits"
-    )
-    try:
-        spectrum_mef.writeto(fits_filename, overwrite=True, output_verify="exception")
-        # TODO: think about overwrite
-        logger.info(f"Wrote {fits_filename}")
-    except:
-        raise
-
-    return
-
-
-def compile_header(wavelength_data, **spectra_data_info):
-    """Creates a header from a dictionary of values."""
+    """
 
     required_keywords = [
         "VOCLASS",
@@ -81,7 +41,7 @@ def compile_header(wavelength_data, **spectra_data_info):
         "observatory",
     ]
 
-    keywords_given = list(spectra_data_info.keys())
+    keywords_given = list(original_header_dict.keys())
 
     for key in keywords_given:
         if key not in required_keywords:
@@ -89,7 +49,7 @@ def compile_header(wavelength_data, **spectra_data_info):
         else:
             pass
 
-    history = spectra_data_info["history"]
+    history = original_header_dict["history"]
 
     comment = "To read this file in with specutils use Spectrum1D.read() with format = 'tabular-fits'"
 
@@ -97,26 +57,26 @@ def compile_header(wavelength_data, **spectra_data_info):
     header.set("EXTNAME", "PRIMARY", "name of this extension")
 
     try:
-        header.set("VOCLASS", spectra_data_info["voclass"], "VO Data Model")
+        header.set("VOCLASS", original_header_dict["voclass"], "VO Data Model")
     except KeyError:
         logging.warning("No VO Data Model")
 
     # Target Data
     try:
         header.set(
-            "OBJECT", spectra_data_info["object_name"], "Name of observed object"
+            "OBJECT", original_header_dict["object_name"], "Name of observed object"
         )
     except KeyError:
         logging.warning("No object name")
 
     try:
-        ra = spectra_data_info["RA"]
+        ra = original_header_dict["RA"]
         header.set("RA", ra, "[deg] Pointing position")
     except KeyError:
         logging.warning("No RA")
         ra = None
     try:
-        dec = spectra_data_info["dec"]
+        dec = original_header_dict["dec"]
         header.set("DEC", dec, "[deg] Pointing position")
     except KeyError:
         logging.warning("No DEC")
@@ -124,8 +84,8 @@ def compile_header(wavelength_data, **spectra_data_info):
 
     try:
         time = (
-            Time(to_datetime(spectra_data_info["start_time"])).jd
-            + Time(to_datetime(spectra_data_info["stop_time"])).jd
+            Time(to_datetime(original_header_dict["start_time"])).jd
+            + Time(to_datetime(original_header_dict["stop_time"])).jd
         ) / 2
         header.set("TMID", time, "[d] MJD mid expsoure")
     except KeyError:
@@ -133,40 +93,40 @@ def compile_header(wavelength_data, **spectra_data_info):
         logging.warning("No time")
 
     try:
-        exposure_time = spectra_data_info["exposure_time"]
+        exposure_time = original_header_dict["exposure_time"]
         header.set("TELAPSE", exposure_time, "[s] Total elapsed time")
     except KeyError:
         exposure_time = None
         logging.warning("No exposure time")
 
     try:
-        time_start = Time(to_datetime(spectra_data_info["start_time"])).jd
+        time_start = Time(to_datetime(original_header_dict["start_time"])).jd
         header.set("TSTART", time_start, "[d] MJD start time")
     except KeyError:
         time_start = None
 
     try:
-        time_stop = Time(to_datetime(spectra_data_info["stop_time"])).jd
+        time_stop = Time(to_datetime(original_header_dict["stop_time"])).jd
         header.set("TSTOP", time_stop, "[d] MJD stop time")
     except KeyError:
         time_stop = None
 
     try:
-        obs_location = spectra_data_info["observatory"]
+        obs_location = original_header_dict["observatory"]
         header.set("OBSERVAT", obs_location, "name of observatory")
     except KeyError:
         obs_location = None
         logging.warning("No observatory")
 
     try:
-        telescope = spectra_data_info["telescope"]
+        telescope = original_header_dict["telescope"]
         header.set("TELESCOP", telescope, "name of telescope")
     except KeyError:
         telescope = None
         logging.warning("No telescope")
 
     try:
-        instrument = spectra_data_info["instrument"]
+        instrument = original_header_dict["instrument"]
         header.set("INSTRUME", instrument, "name of instrument")
     except KeyError:
         instrument = None
@@ -180,7 +140,7 @@ def compile_header(wavelength_data, **spectra_data_info):
     w_mid = ((w_max + w_min) / 2).astype(np.single)
 
     try:
-        bandpass = spectra_data_info["bandpass"]
+        bandpass = original_header_dict["bandpass"]
         header.set("SPECBAND", bandpass, "SED.bandpass")
     except KeyError:
         bandpass = None
@@ -196,14 +156,14 @@ def compile_header(wavelength_data, **spectra_data_info):
     header.set("TDMAX1", w_max, f"[{w_units}] Ending wavelength")
 
     try:
-        aperture = spectra_data_info["aperture"]
+        aperture = original_header_dict["aperture"]
         header.set("APERTURE", aperture, "[arcsec] slit width")
     except KeyError:
         aperture = None
         logging.warning("No aperature")
 
     try:
-        obs_date = to_datetime(spectra_data_info["obs_date"]).strftime("%Y-%m-%d")
+        obs_date = to_datetime(original_header_dict["obs_date"]).strftime("%Y-%m-%d")
         header.set("DATE-OBS", obs_date, "date of the observation")
     except KeyError:
         print(KeyError)
@@ -212,30 +172,30 @@ def compile_header(wavelength_data, **spectra_data_info):
 
     # Publication Information
     try:
-        title = spectra_data_info["title"]  # trim so header wraps nicely
+        title = original_header_dict["title"]  # trim so header wraps nicely
         header.set("TITLE", title, "Data set title")
     except KeyError:
         pass
         logging.warning("No title")
 
     try:
-        header.set("AUTHOR", spectra_data_info["author"], "Authors of the data")
+        header.set("AUTHOR", original_header_dict["author"], "Authors of the data")
     except KeyError:
         pass
         logging.warning("No author")
 
     try:
-        header.set("VOREF", spectra_data_info["bibcode"], "Bibcode of dataset")
+        header.set("VOREF", original_header_dict["bibcode"], "Bibcode of dataset")
     except KeyError:
         pass
 
     try:
-        header.set("REFERENC", spectra_data_info["doi"], "DOI of dataset")
+        header.set("REFERENC", original_header_dict["doi"], "DOI of dataset")
     except KeyError:
         pass
 
     try:
-        header.set("VOPUB", spectra_data_info["VOPUB"], "VO Publisher")
+        header.set("VOPUB", original_header_dict["VOPUB"], "VO Publisher")
     except KeyError:
         logging.warning("No VO Publisher")
 
@@ -252,3 +212,52 @@ def compile_header(wavelength_data, **spectra_data_info):
     header.set("DATE", date.today().strftime("%Y-%m-%d"), "Date of file creation")
 
     return header
+
+
+def convert_to_fits(
+    wavelength=None,
+    flux=None,
+    flux_unc=None,
+    header: dict = None,
+    out_directory: str = ".",
+):
+    """Converts a spectrum to a fits file.
+    # TODO: add typehits for astropy quantities
+
+    wavelength: an array of wavelengths with units
+    flux: an array of fluxes with units
+    flux_unc: an array of flux uncertainties with units
+    header: a dictionary of header values made with compile_header function
+
+    """
+
+    object_name = header["OBJECT"]
+
+    header["HISTORY"] = "File made with the simple.spectra.convert_to_fits.py function"
+
+    spectrum_data_out = Table(
+        {
+            "wavelength": wavelength,
+            "flux": flux,
+            "flux_uncertainty": flux_unc,
+        }
+    )
+
+    # Make the HDUs
+    hdu1 = fits.BinTableHDU(data=spectrum_data_out)
+    hdu1.header["EXTNAME"] = "SPECTRUM"
+    hdu1.header.set("OBJECT", object_name, "Object Name")
+    hdu0 = fits.PrimaryHDU(header=header)
+
+    # Write the MEF with the header and the data
+    spectrum_mef = fits.HDUList([hdu0, hdu1])  # hdu0 is header and hdu1 is data
+
+    fits_filename = out_directory + object_name + "_" + header["DATE-OBS"] + ".fits"
+    try:
+        spectrum_mef.writeto(fits_filename, overwrite=True, output_verify="exception")
+        # TODO: think about overwrite
+        logger.info(f"Wrote {fits_filename}")
+    except:
+        raise
+
+    return